Research On “Moving Treaty Frontier” Rule

If the contracting parties of a treaty do not specify the territorial scope to which the treaty applies,the "Moving Treaty Frontier" rule will often play a role when such disputes arise.The "Moving Treaty Frontier" rule means that when the sovereignty of part of a contracting party’s territory changes,the treaty system to which this part of the territory applies will also change.Under normal circumstances,the treaty system applicable to the territory where the sovereignty has changed should be moved from the predecessor state to the successor state.That is,the treaty system of the successor state should apply to the entire territorial scope of the successor state,including the territorial scope newly obtained by the successor state.This situation describes the general situation of the application of the “Moving Treaty Frontier” rule.In addition,if the successor state’s treaty clearly states the territory to which it applies,or if the successor state and the contracting party reach a new agreement on the scope of the treaty’s application of the territory,the treaty system to which this territory applies will no longer transfer with sovereignty,and the treaty of the successor state is no longer applicable to this territory.The result is that the successor state’s treaty no longer applies to the entire territorial scope of the successor state,and this situation is known as the exception to the rule applicable to the "Moving Treaty Frontier" rule.The "Moving Treaty Frontier" rule is mainly embodied in Article 15 of the Vienna Convention on Succession of States in Treaties and Article 29 of the Vienna Convention on the Law of Treaties.These two treaty articles are generally regarded as the main content of the "Moving Treaty Frontier" rule at the international level.In current state practice,the "Moving Treaty Frontier" rule is often identified as customary international law.Singapore courts played an important role in adjudicating the "Moving Treaty Frontier" rule in Macau’s "SANUM" case.In 2013,the arbitral tribunal determined that the China-Laos Bilateral Investment Agreement applies to Macau.However,the Lao government refused to accept the adjudication and submitted the dispute to the Supreme Court of Singapore in 2014,The Supreme Court of Singapore supported the Laotian government’s claim that the China-Laos Bilateral Investment Agreement is not applicable to the Macao Special Administrative Region.SANUM immediately appealed,and the Singapore Court of Appeal stated in its judgment in September 29,2016 that the China-Laos Bilateral Investment Agreement is applicable to the Macao Special Administrative Region and rejected the Lao Government’s proposal to withdraw the arbitral decision.Due to the fact that Macau’s return to China concerns territorial change,the "Moving Treaty Frontier" rule was mentioned when the Singapore Court of Appeal was determining whether the China-Laos Bilateral Investment Agreement applies to Macau or not.Through the analysis of the theory and the practice of the "Moving Treaty Frontier" rule,the author believes that whether the “Moving Treaty Frontier” rule applies to the region of Macau should be considered from the following points.First of all,it is necessary to figure out the nature of Macau’s return and analyze whether it falls within the scope of application of the "Moving Treaty Frontier" rule.Second,as for the territorial transfer of Macau,it is the first time a new form has appeared that territory is transferred in one state with two different social systems,therefore it is necessary to reanalyze the nature of the "Moving Treaty Frontier" rule.Finally,on the issue of the transfer of territories involved in the return of Hong Kong and Macau,because it is not convincing that the "Moving Treaty Frontier" rule is the nature of customary international law,there is a great deal of uncertainty in applying it.Therefore,the way to avoid the uncertain situation is by analyzing the pros and cons of Chinese and foreign bilateral investment agreements applicable to Hong Kong and Macau.The conclusion is that using the “general rules” of the “Moving Treaty Frontier” rule,it is determined that the Chinese-foreign bilateral investment agreement applies to Hong Kong and Macau;using the "exclusion" of the "Moving Treaty Frontier" rule,it is determined that the Chinese and foreign bilateral investment agreement does not apply to Hong Kong and Macau.